I'm developing recommendations for local councils publishing event listings. Compared to other kinds of data, events data seems very likely to be used by web and mobile apps (as opposed to downloaded for analysis), and is inherently chronologically ordered and time sensitive.

I'm really not sure which format to recommend:

CSV is the format I recommend for most non-spatial data. It's easy to process and supported by lots of software.

JSON is the preferred format of web and mobile developers.

RSS remains probably the most widely used format for feeds of information like blog posts

Atom is a better format than RSS, but from memory is a bit more work.

Are there any recommendations on the topic I can follow?

EDIT

By "events", I mean public events like concerts, workshops, festivals etc. They generally have specific locations, but the people that produce the data don't seem to include lat/longs.

The real test is to determine who the largest consumer of your dataset is going to be, and then determine what they want/how they will use it. If there are going to be thousands of people pulling it into their RSS feeder, that trumps the 100 who consume the CSV. If you expect app devs to want to integrate, then giving them a JSON endpoint will make that easy. It also begs the question why not push out multiple formats. Most modern web frameworks will give multiple renderings for free (as in free beer). But each has its merits and is tailored for a different use case.
– Shawn MehanNov 24 '15 at 16:45

What type of events are we talking about? Stuff like meetings, festivals, concerts and such? Or even things like which days are trash picked up, or deadlines (taxes paid, registering for an election)? Or are they monitoring type events (police/crime reports). For anything in the future where you're notifying the general population, I'd recommend looking into calendar formats (hCalendar, vCalendar, iCalendar, etc.). It's just been so long since I've used 'em that I don't know which are the most popular / easily consumed these days.
– JoeNov 24 '15 at 21:52

Its relatively painless to convert from JSON to CSV and vice-versa. what matters is the structure of your data. If its properly formatted, you should have very little problems converting/conforming to standardized formats.

Speaking of formatting, you should keep in mind that RSS is a great route to go here, but thats more for consumption via apps than humans. When converting to JSON/CSV/RSS/etc., you should also port this out to HTML, using the correct markup (typically <table>, perhaps <ol>), while also applying semantic attributes to make the data more portable. In this case, I'd use microformats to mark up the events, so I'd apply hCalendar, as well as hEvent, and when possible, hCard and others that are applicable per event (I'm sure that will vary for each).

Whichever route you choose, I'd also be keen to implement Add To Calendar functionality for each event; what I mean is, on a page with an event on it, give users the option to add the event to their calendar, pretty much exactly how eventbrite and meetup do when you are on an events page.

W3C is working on making JSON and CSV web standards, as well as Linked Data standards for both, so again there is no wrong answer here.

Keeping the data well structured (aka prepped and ready) will allow it to be ported to standardized/supported formats, literally as many as you want to convert to. Which facilitates the spread of information, as your data is now extremely portable.

Just to add another format: iCalender (.ics) might be a nice add-on if the events are to be booked/bookmarked/scheduled by visitors interested in attending some/all of the events. Although the support for spatial data is limited to a plaintext field, it might be worth adding.

I would go with CSV. It will help your clients reach most of the audiences they interact with on a regular basis. There is no shortage of packages to read, arrange, and manipulate CSV files in languages like R and Python, which the data diggers will love. The less computer-literate will at least be able to open a CSV in a spreadsheet reader or text file application.